Answer:
Number of moles of iron are 4 mol.
Explanation:
Given data:
Mass of iron = 223.4 g
Number of moles = ?
Solution:
Molar mass of iron = 55.85 g/mol
Formula:
Number of moles = mass/molar mass
Number of moles = 223.4 g/ 55.85 g/mol
Number of moles = 4 mol
The formula for average atomic mass is :
mass of isotope A * % of isotope A + mass of isotope B * % of isotope B + ....
Now,
Here,
Average atomic mass of nitrogen = (14.003 * 99.63%) + (15.000 * 0.37%)
= (14.003 * 0.9963) + ( 15.000 * 0.0037)
= 13.951 + 0.056
= 14.007 a.m.u.
Answer:
Explanation:
E=hf 2.3x10^-15 J=(6.63x10^-34 J/Hz)f
<span>Gold is actually very soft. If rings were made of pure gold they would bend and become disfigured. Other elements are added to give the ring its stability.</span>